The invention concerns a sealing arrangement for shafts with small diameters within or bordering on housings containing mediums, where a lip seal is loaded by an axially acting spring.
The general prior art includes axial face seals for centrifugal pumps. The characteristic of this type of seal is that the moving sealing surface which is subject to wear has been relocated away from the shaft surface into a surface perpendicular to the shaft axis. The actual seal is established between the surfaces of a fixed ring and a rotating sliding ring. The latter is axially acted upon by a spring force. A fixed-body contact exists during operation between the sliding surfaces, so that a gap is no longer present (refer to Dubbel, pp. 197, 198 "Gleitringdichtungen" [axial face seals]).
Also known from the prior art is loading the seal by means of a worm spring in order to thereby obtain the necessary contact pressure for the desired seal. But it has been demonstrated that inserting such a worm spring is for space reasons not possible with very small shaft diameters.
Exactly with very small shaft diameters and high shaft peripheral speeds along with high liquid or gas pressures it was heretofore considered as impossible that with high peripheral speeds of the shaft to be sealed and with high pressures an effective sealing arrangement could be employed. The illustrated operating conditions regularly led to a relatively quick aging of the seals employed, whereby their resilience was lost, particularly at the seal lips. The result was leakages and liquid penetration at the transmission parts and engines connected to the shafts.
The problem underlying the invention is to provide a sealing arrangement for shafts with small diameters of the initially named type, which arrangement is simple in its entire structure, additionally allows a simple assembly and assures an optimum effect also over a long period of time while avoiding the disadvantages of the said prior art.